BIOLOGY; 



OR, PHYSIOLOGY, ZOOLOGY, AND BOTANY. 



DERIVATIVE nYPOTHESIS OF LIFE AND SPECIES. BY PROP. 



OWEN. 



In his recently published work on the *• Anatomy of Vertebrates," 

 Prof. Owen devotes a chapter to his hypothesis of the origin of 

 species, as contrasted with the theory of Danvin. This chapter 

 is reprinted in the "American Journal of Science" for J anuaiy, 

 1869 ; and from this the following extracts are made : — 



*' Prof. Owen, like Lamarck and Darwin, rejects the principle of 

 direct or miraculous creation, and recognizes a ' natural law, or 

 secondary cause,' as operative in the production of species ' in 

 ordt.'rly succession and progi*ession.' To Cuvier's objection, tliat, 

 if the existing species are modifications, by slow degrees, of ex- 

 tinct ones, the intermediate lorms ought to be found, he replies, 

 that many missing links in the palajontological series have been 

 found since 1830. He gives several examples of these modilica- 

 tions, and dwells specially on hipparioiiy and the other forms 

 between the fossil palceotherium and the present genus equus. 



*• Cuvier maintained that the revolutions of the suiiace of the 

 globe had been numerous and sudden. Owen writes, * Continued 

 observations of geologists, while establishing the fact of succes- 

 sive changes, have tilled up the seeming chasms between such 

 supposed "revolutions," as the discoveries of pala?ontologists have 

 supplied the links between the species held to have perished by 

 the cataclysms. Each successive parcel of geological truth has 

 tended to dissipate the belief in the unusually sudden and violent 

 nature of the changes recognizable in the earth's surface.' " 



Lamarck laid great stress upon the influence of surrounding 

 circumstances in modifying the habits and structure of living 

 beings. In this connection, Owen observes, taking the coral ani- 

 mals as illustrations, the hypothesis "of appetency subsides 

 from the impotency of a coral polyp to exercise volition. The 

 weak point of Lamarck's creative machinery is its limited applica- 

 bility, namely, to creatures high enough in the scale to be able to 

 want to do something; for the determined laws of the reflex 

 function, in the physiology of the nervous system, and the neces- 

 sity of the superadded cerebral mass for true sensation, rigorously 

 fix the limits of volitional faculties." So, being "unable to accept 



2G8 



